This invention relates generally to a machine for severing standing crops from the ground to initiate a harvesting process and, more particularly, to a cutterbar having a preselected number of low-profile, modular rotary cutter units mountable on a movable frame which allows the cutterbar width to reduced for transport.
One common type of modular disc cutterbars used in agriculture includes a plurality of individual rotary disc cutter modules, each having a self-contained drive mechanism, modularly interconnected by spacers and drive shafts spanning a header to form the cutterbar. The modular nature of the cutter modules isolates contamination of the drive mechanism occurring in the event of a failure of a single cutter module. Limiting the spread of debris from a failed module reduces the corrective maintenance necessary to replace the failed module. The disadvantage to a modular design of this type is that a higher profile (compared to other designs) cutterbar is necessitated by the space for a transverse shaft driveline interconnecting adjacent cutter modules. Higher profile cutterbars tend to negatively influence crop flow across the cutterbar and into the header.
Cutterbars frequently impact rocks and other obstructions in a field which can damage the cutterhead or the cutterhead driveline. Modular cutterhead designs allow an individual damaged cutterhead to be removed and replaced without affecting adjacent cutterhead modules. The modular design contains debris from gear failures within an individual module oil sump and reduces debris contamination of adjacent modules. However, replacing a single damaged cutterhead module is not an insignificant task requiring significant disassembly of the cutter bar in order to remove a damaged cutterhead from the cutterbar driveline because of intermediate drive shafts disposed between adjacent modules to transfer power laterally along the cutterbar.
Known gear-driven cutterbar designs generally include an elongate housing containing a train of meshed idler and drive spur gears for delivering power from one or more input shafts to respective cutterheads spaced along the length of the cutterbar. The housing typically extends substantially the entire transverse width of the cutterbar. The cutterheads each comprise a cutting disc including diametrically opposed cutting blades (though configurations with three or more blades are known) and having a hub coupled to an upper end of a drive shaft, the lower end of the drive shaft carrying a spur gear intermeshed with the drivetrain spur gears. Known gear-driven cutterbars cannot be folded or otherwise reconfigured to allow the cutterbar width to be reduced in order to improve transportability of a harvester between distant field locations.
It would be advantageous to have a modular cutterbar design incorporating the low profile advantages of a gear-driven driveline and the modularized housings which compartmentalize the drive-train housing in order to limit the spread of debris following a failure in one of the cutterheads and further to reduce the degree of cutterbar disassembly necessary to remove and replace a damaged module. Further advantages would be realized by a cutterhead module design that would allow variations in cutterbar width by varying the number of modules used thereby enabling one module design to be used on a number of cutterbars. Still further advantages would be realized in a cutterbar having multiple modules by mounting the modules on a movable frame that would allow a cutterbar width to be reduced to facilitate transport.